Figure 4 - figure supplement 1

VMP1 is required for secretion and homeostasis of lipoproteins but not for formation of cartilage structures in the zebrafish head skeleton.

(A and B) HepG2 cells were treated with siRNA against luciferase (Luc) or VMP1 and cultured in 0.1% bovine serum albumin (BSA) containing media with or without 200 μM oleic acid for 2 days. Triglycerides- (A) and cholesterols-containing lipoproteins (B) in medium were fractionated by chromatography and analyzed. CM, chylomicron; VLDL, very-low-density lipoprotein; LDL, low-density lipoprotein; HDL, high-density lipoprotein. Data represent the mean ± standard error of the mean (n = 3). (C) HepG2 cells were treated as in (A) and cultured in serum-free medium containing 200 nM oleic acid in the presence or absence of 5 μM lactacystin for 24 hr. The medium was concentrated by TCA precipitation. Samples (approximately 7% or 14% vol of total precipitated media or cell lysates, respectively) were subjected to immunoblot analysis. The amount of APOB was quantified through densitometric scanning of bnd intensities. Data represent the mean ± standard error of the mean (n = 4), which was normalized to siLuc, and statistically analyzed using the Student’s t-test (*, p<0.05).